Engine starter



Feb. 3, 1931 M. JACKSON ET AL 1,791,273

ENGINE STARTER Filed Oct. 24, 1929.

if fiz upon the Patented Feb. 3, 1931 camp s mrss esrssr orr es MAUNSELL :e. JACKSON AND KE NETH M. CLIPSHAM, or TORONTO, ONT IO, oANAiiA; SAID GLIPSHAM ASSIGNOR TO LEASIDE ENGINEERING o0. LIMITED, on mission,

ONTARIO, CANADA ENGINE STARTER Application filed October 24, 1929. Serial No. 402,237.

This invention relates to engine starters and more particularly to the inertia type of starter in which the starter pinion is mounted on a screw shaft so that it will be moved by the rotation of the shaftlongitudinally thereof into r'rsh with an engine gear and will then be. rotated with the shaft to drive the gear. In this type of startorwhen the teeth of the pinion abut the teeth of the gear, the

pinion is supposed to be rotated by the shaft until its teeth clear the gear teeth, wheretinned until the latter is fully meshed with the gear. If theforce tending to rotate the pinion be not sullicient to rotate it in. the

above mentioned case where the teeth of the pinion abut the teeth of the gear thepinion will be forced axially, by means of the screw shaft turning through the non-rotating pinion, against the gear and which *willqcause the screw shaft tobe forced back-to cramp or jam against its bearingand the engine crankshaft, on which the gear 18 carried, to be forced forwardly to 1am against its bear .ingrs which will result in the starter mot-oi:

being stopped. This is the well known jam of inertia or Bendix type of start rs and is frequently ofsuch intensity that the engine cannot be cranked by handto releive the jam. The object of the present invention is to provide a starter, of-this character which will overcome the above objectionable features. V

o attain our object by providing an are ially movable member, which may be the armature shaft of the starter motor or a sleeve thereon. The starter pinion is threaded on the member so that in case of collision between the pinion and the engine to cause the crankshaft of the engine, which i l movement of the pinion is con ion and part of the. gear shownn F Fig.5 showing with the gear.

shaft Elwill feed the pinion along the shaft 'untilit is fully ineshecl withthe'gear, which shaft carries the gear, to jam against its bearings. 1 I

The constructions are hereinafter more fully described and illustrated in the accon'v p'anyingl drawin in which i 1 Fig. l is a side elevation, par ly in section, of part of our starter showing' the parts. in their normal or inoperative positions;

Fig. 2 a longitudinal section of part of thejstarter showing thepinioii and flange in contact'with the gear, Fig; 3 an end. elevationof the llange, pin

7 Fig. 4; .a detail in side elevatio howing the pinion fully in mesh with the gear;

Fig. 5 a side elevation, a rtly in section, of a modified form of our starter; and f Fig. 6 a side elevation of the parts shown in the pinion fully meshed with thegear. i Y I 7D In the drawings-like numeral-sbf reference indicate corresponding parts in'the different figures. q

1' is a starter motor provided with an axially movable armature shaft 2 whichv journalled in. the bearings 3,4 and 5. 01i" the shaft is-threaded apinion 6 which is moved along the shaft, by the rotation of the latter relative to the pinion, towards a gear 7 of the engine to be started.- This gear is generally formed on or securedctol the fly 7 wheel '(not shown) of the engine and-the liy wheel is secured to the engine crankslnilt (not shown). p I Should the teetho'lf' the pinion (5 register with the spaces between the teeth of the gear 7, the pinion will be moved directly into mesh The gear teeth willprevcnt rotation of the pinion and the thread on the position is determined by an abutment formed as a flange 8 carriedbythe shaft. When the axial movement of the pinion is stopped the pinion will be rotated with'the shaft to 9. drive the gear.

In the'case where the pinionteeth abutthe gear teeth and the rotary movement ,"of "the pinion is stoppech the shaft-will be threaded back through the pinion as in other inertia 1 starters but in our starter the shaft is prevented, by means of the flange 8 which en gages the ends of the gear teeth opposite the ends engaged by the pinion, from retreating far enough to cramp or jam the starter motor bearings. The gear is thus trictionally clamped between the flange and the pinion so that the thrust against one side of the gear is equal to the thrust against the other side thereof. I-Ieretoi'ore in a case of this description, the pinion was pressed against the gear with such force that the armature shaft was axially forced in one direction until the thrust between the armature hub or collar-9 and the bearing 8 was sufficient to stop the motor. In addition to this jam there was also an axial movement of the gear in a direc tion opposite to that of the armature shaft which caused a j am between the crankshaft oi the engine and its bearings (not shown).

With our starter it is obvious that the flange 8 limits-the axial movement of the shaft 2 so that the armature hub or collar 9 will not be thrust against the bearing 3, and that the gripping oi the opposite sides of the gear prevents the pinion from moving); the gear axially to cause a jam between the engine cran shaft and its bearings. The frictional grip on the flywheel gear should it not slip will turn the gear either to start the engine or permit the pinion teeth to slide into mesh with the gear teeth without damage to the parts.

In Figs. 5 and 6 we show a modified r rangement in which the armature shaft 2 is mounted in the usual mannerwithout allowance for axial movement. 8n the shaft 2 is feather-keyed 2" WlllCD. is provided with a flange 9 and has the pinion 6 threaded thereon. Should the pinion teeth collide with the gear teeth the sleeve will be threaded through the pinion to relieve the axial thrust between the pinion and gear. The flange 9'' limits this axial movement otthe sleeve and prevents the end thereof from being thrust against the bearing 5. The manner of bold ing the gear from axial movement by the pinion is the same as that described for the preferred form of our invention.

In both the preferred and modified terms of the starters, the pinion 6 will be automatically de-meshed when the engine started and before ejection takes place the member 2 or 2" will be returned to its initial position. When the engine starts the speed of the gen r drives the pinion at a greater speed than that of the shaft 2 or sleeve 2 whereby the latter will be moved axially until a collar 10 or flange 9 engages the bearing 5 or abutment 10 respectively. The pinion will then demeshed from the gear.

In Figs. 4 and 6 the pinion 6 is shown fully meshed with the gear 7 in the position it would take ust before the gear is driven.

Vhat we claim is:

1. In an engine s arter drive the combination with a r o't an engine to be started, of a rotatable and axially movable ineniher, a starter pinion threaded thereon whereby the pinion moved longitudinally towards the gear by the rota ion oi the memher and the member moved axially in case the pinion collides with the gear; and means carried by the member for engaging the side of the remote from the pinion to limit the axial movement of the member.

2. In an engine starter drive the combination with a gear of an engine to be started, of a rotatable and axially movable member, a starter pinion threaded thereon whereby the pinion is moved longitudinally towards the gear by the rotation of the member and the mend or is moved axially in case the pinion. colli les with the gear; and a flange carried by the member for engaging the side of the gear remote from the pinion to limit the axial movement oi the member.

3. In an engine starter drive the combination. with a gear of an engine to be started, 01 a starter motor; an axially movable member rotatably driven by the starter motor; a starter pinion threaded on the member whereby the pinion moved longitudinally towarus the gear by the rotation 01 the member and the member is moved axially in case the pinion collides with the gear; and flange carried by the member for engaging the side of the gear remote from the pinion if the latter fails to mesh with the gear whereby the pinion and flange will tend to clamp the gear between them.

In an engine starter drive the combina tion with a gear of an engine to be started, of a starter motor l'mvingr an axially niovable arn'iature shaft join-nailed therein; a starter pinion threaded. on the shaft for lonudinal movement toward the gear by the ,tion of the shaft and for moving the shaft axially in case the pinion collides with the gear; and a flange carried by the shaft for engagen'ient with the side of the gear re 1no;e from the pinion to limit the axial movement of the shaft whereby the gear will be clamped by the pinion and flange to prevent the armature shaft from jan'nning against its bearings. I

Signed at Toronto, Canada, this 19th day of October, 1929.

MAUIISELL B. JACKSON. KENNETH M.. GLIPSI'IABI.

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